Submitted as: development and technical paper11 Dec 2020
Submitted as: development and technical paper | 11 Dec 2020
Review status: this preprint is currently under review for the journal GMD.
Grid-independent High Resolution Dust Emissions (v1.0) for Chemical
Transport Models: Application to GEOS-Chem (version 12.5.0)
Jun Meng1,2,Randall V. Martin2,1,3,Paul Ginoux4,Melanie Hammer2,1,Melissa P. Sulprizio5,David A. Ridley6,and Aaron van Donkelaar1,2Jun Meng et al.Jun Meng1,2,Randall V. Martin2,1,3,Paul Ginoux4,Melanie Hammer2,1,Melissa P. Sulprizio5,David A. Ridley6,and Aaron van Donkelaar1,2
Received: 19 Nov 2020 – Accepted for review: 10 Dec 2020 – Discussion started: 11 Dec 2020
Abstract. The nonlinear dependence of the dust saltation process on wind speed poses a challenge for models of varying resolutions. This challenge is of particular relevance for the next generation of chemical transport models with nimble capability for multiple resolutions. We develop and apply a method to harmonize dust emissions across simulations of different resolutions by generating offline grid-independent dust emissions driven by native high-resolution meteorological fields. We implement into the GEOS-Chem chemical transport model a high-resolution dust source function to generate updated offline dust emissions. These updated offline dust emissions based on high-resolution meteorological fields can better resolve weak dust source regions, such as in southern South America, southern Africa, and the southwestern United States. Identification of an appropriate dust emission strength is facilitated by the resolution independence of offline emissions. We find that the performance of simulated aerosol optical depth (AOD) versus measurements from the AERONET network and satellite remote sensing improves significantly when using the updated offline dust emissions with the total global annual dust emission strength of 2,000 Tg yr−1 rather than the standard online emissions in GEOS-Chem. The offline high-resolution dust emissions are easily implemented in chemical transport models. The source code is available online through GitHub: https://github.com/Jun-Meng/geos-chem/tree/v11-01-Patches-UniCF-vegetation . The global offline high resolution dust emission inventory is freely available (see Code and Data Availability section).
Global High Resolution Dust Emission Inventory for Chemical Transport ModelsJun Meng, Randall V. Martin, Paul Ginoux, David A. Ridley, and Melissa P. Sulprizio https://doi.org/10.5281/zenodo.4060248
Observations of AOD and GEOS-Chem simulation model output datasetJun Meng, Randall V. Martin, Melanie Hammer, Aaron van Donkelaar, Paul Ginoux, and David A. Ridley https://doi.org/10.5281/zenodo.4312944
Dust emissions in models, for example, GEOS-Chem, have a strong nonlinear dependence on meteorology, which means dust emissions calculated from different resolution meteorological fields are different. Offline high-resolution dust emissions with a scalable total annual dust strength, presented in this work, can be implemented into GEOS-Chem easily so that it could promote model development by harmonizing dust emissions across simulations of different resolutions.
Dust emissions in models, for example, GEOS-Chem, have a strong nonlinear dependence on...